feat(desktop): P28 整图 2px/tile 真实帧取证钩子

- LV_MAPGEN_FIT_WIDTH/HEIGHT 额外渲染整图到指定像素目标（1024x768 -> 恰 2px/tile）
- 仅取证模式触发，不进入正常游戏循环

1 files changed, 18 insertions, 0 deletions

diff --git a/src/LivingVillage.Desktop/Game.fs b/src/LivingVillage.Desktop/Game.fs
index 591d1b9..824c1c1 100644
--- a/src/LivingVillage.Desktop/Game.fs
+++ b/src/LivingVillage.Desktop/Game.fs
@@ -296,6 +296,15 @@ type LivingVillageGame() as this =
         match Environment.GetEnvironmentVariable("LV_MAPGEN_SEED") with
         | null | "" -> 4242UL
         | v -> match UInt64.TryParse v with (true, value) -> value | _ -> 4242UL
+    // P28 证据钩子：额外把整图按指定像素目标渲染一次（用于 1 tile≈2px 的缩放可读性取证）。
+    let mapGenFitWidth =
+        match Environment.GetEnvironmentVariable("LV_MAPGEN_FIT_WIDTH") with
+        | null | "" -> 0
+        | v -> match Int32.TryParse v with (true, value) when value > 0 -> value | _ -> 0
+    let mapGenFitHeight =
+        match Environment.GetEnvironmentVariable("LV_MAPGEN_FIT_HEIGHT") with
+        | null | "" -> 0
+        | v -> match Int32.TryParse v with (true, value) when value > 0 -> value | _ -> 0
     let mutable mapGenResult = Unchecked.defaultof<MapGen.Result>
     let mutable mapGenGenMs = 0.0
 
@@ -891,6 +900,15 @@ type LivingVillageGame() as this =
         fittedTexture.SaveAsPng(stream, fittedTexture.Width, fittedTexture.Height)
         printfn "mapgen-fitted drawn=%d png=%dx%d" fittedDrawn fittedTexture.Width fittedTexture.Height
 
+        // P28：整图按指定像素目标再渲染一次（真实帧）。1024x768 -> 512x384 图恰为 2px/tile，
+        // 用于证明两民居变体在「整图 1 tile≈2px」缩放下肉眼可分。
+        if mapGenFitWidth > 0 && mapGenFitHeight > 0 then
+            let fitDrawn, fitTexture = this.RenderMapGen mapGenFitWidth mapGenFitHeight 0 0 true
+            use _fit = fitTexture
+            use fitStream = System.IO.File.Create(sprintf "%s/p28-fit-%dx%d-seed%d.png" recordDirectory mapGenFitWidth mapGenFitHeight (int mapGenResult.Seed))
+            fitTexture.SaveAsPng(fitStream, mapGenFitWidth, mapGenFitHeight)
+            printfn "mapgen-fit drawn=%d png=%dx%d" fitDrawn mapGenFitWidth mapGenFitHeight
+
         let clampRange maximum value = max 0 (min (max 0 maximum) value)
         let camX = clampRange (mapGenResult.Width * Sim.tilePixels - viewport.Width) ((mapGenResult.Width * Sim.tilePixels - viewport.Width) / 2)
         let camY = clampRange (mapGenResult.Height * Sim.tilePixels - viewport.Height) ((mapGenResult.Height * Sim.tilePixels - viewport.Height) / 2)